Generator regulation employing auxiliary interpole winding



y 1954 A. D. GILCHRIST 2,685,057

GENERATOR REGULATION EMPLOYING AUXILIARY INTERPOLE WINDING Filed Feb. 1, 1952 2 Sheets-Sheet l fie. 1

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Hill NIH IN VEN TOR. AL 55w 0 6/4 cwn/sr i MM%df7 Arromvsys July 27, 1954 A. D. GILCHRIST GENERATOR REGULATION EMPLOYING AUXILIARY INTERPOLE WINDING 2 Sheets-Sheet 2 Filed Feb. 1, 1952 Q INVEN TOR.

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Patented July 27, 1954 GENERATOR REGULATION EMPLOYING AUXILIARY INTERBOLE WINDING Albert D. Gilchrist, Lyndhurst, Ohio, assignor to The Lecce-Neville a corporation of Ohio Company,

Cleveland, Ohio,

Application February 1, 1952, Serial No. 269,498

4 Claims.

This invention relates to electrical generating systems and, more particularly, to generating systems embodying novel voltage and current regulating means. The invention is of particm lar utility with reference to generators operating through a wide range of speed such as the generators of vehicle electrical systems. Accordingly, the invention is disclosed herein as applied to a vehicle electrical system, but without any intention of limiting the invention thereto since it is also applicable to various other uses.

An object of the invention is to provide an improved electrical generating system embody ing a generator of the interpole type and a regulator of the electromagnetic vibratory contact type, and in which the field excitation of the generator is responsive to the effect of an auxiliary interpole field winding whose energization is controlled by the regulator.

Another object is to provide an improved generating system of this character in which the energization of the auxiliary interpole field winding under the control of the regulator is a funotion of the generator speed, such that for increased generator speeds a greater flux will be produced by the auxiliary interpole winding to offset the change occurring in the generator reactance voltage with the increase in generator speed.

Still another object is to provide an improved generator-regulator system of the kind above re ferred to in which the regulator comprises a voltage regulator and/or a current regulator.

A further object is to provide an improved generator-regulator system of the character mentioned in which the vibratory switch contacts of the voltage regulator are shunted by a resistor and the excitation of the auxiliary interpole field Winding is substantially in accordance with the voltage drop across the resistor.

It is also an object of this invention to provide an improved generator-regulator system of the type above indicated in which the auxiliary interpole field winding is in series with the main shunt field winding of a direct current generator embodied in the system and produces improved commutation for the generator over a wide speed range.

Yet another object is to provide such an improved generator-regulator system in which the auxiliary interpole field winding is in parallel with the main shunt field winding of the generator.

As an additional object, this invention provides an improved generator-regulator system of the kind mentioned above in which the auxiliary interpole field winding is a bucking winding magnetically opposing the normal interpole flux, such that a substantially correct resultant interpole fiux strength will be produced for the minimum operating speed of the generator and, as the generator speed is increased and the regulator reduces the field current correspondingly, an interpole flux of increased strength will be available for ofisetting the change which occurs in the generator reactance voltage through the increase in generator speed.

Other objects and advantages of the invention will be apparent in the following detailed description and in the accompanying sheets of drawings in which:

Fig. 1 is a wiring diagram showing a generatorregulator system embodying the present invention;

Fig. 2 is a diagrammatic View showing a generator of the interpole type to which the present invention has been applied in the generator-regulator system of Fig. 1; and

Figs. 3 and 4 are wiring diagrams similar to 3 that of Fig. 1, but showing modified forms of such a generator-regulator system.

As one practical embodiment of the present invention, Fig. 1 shows a generator-regulator system which in general comprises a direct current interpole generator l0 and a regulator and out out unit I I connected in circuit with the generator. The unit II in turn comprises a voltage regulator I2, a current regulator l 3 and a reverse current cutout M.

The generator [0 is provided with load terminals which are here shown as being the brushes i5 and I6 of the generator. A pair of load conductors l1 and I 8 are connected with the load terminals l5 and I6 and represent an external load circuit to which various devices to be supplied With current are connected such as the storage battery [9 and the lamps 20. The generator l0 also comprises main shunt field windings 2| and 22 and main series field windings 23 and 24. Additionally, the generator ill comprises control field windings 25 and 25 which are also referred to hereinafter as auxiliary interpole field windings.

The generator 0 is further illustrated in Fig. 2 as having a frame 21 of a conventional construction and which includes a pair of main north and south field pole members 28 and 29 on which the main shunt field windings 2| and 22 are located respectively. The generator frame 27 also includes a pair of north and south interpole magnet pole members 30 and 3| on which the main series field windings 23 and 24 are located respectively. The auxiliary interpole field windings, to which further reference will be made hereinafter, are also located on the interpole magnet pole members Stand 3|.

The voltage regulator i2 comprises an electromagnet which is here represented by the magnet coil 32 and a pair of cooperating vibratory switch contacts 33 and 34 which are operated in response to changes in magnetization produced by the magnet coil. The coil 32 is a voltage coil having one end thereof connected with the generator terminal l through the. conductor and the load conductor IT. The other end of the coil 32 is connected with the generator terminal l3 through a conductor 36 and the load conductor i8. The energizing circuit for the coil 32 preferably also includes a suitable ballast resistor 3?.

The contact 33 of the vibratory switch contacts of the voltage regulator I2 is a stationary contact and the contact 34 is a movable contact which is carried by an armature 33 and is urged toward a position of closed engagement with the stationary contact 33 by a tension spring 33.

The voltage regulator [2 also comprises a point resistor 40 of a suitable resistance value which is contained in the field circuit of the generator l0- and is located in shunt relation to the vibratory switch contacts 33 and 34 so as to be short-circuited by these contacts when they are in their closed position. i

The current regulator 13 is also a regulator of the electromagnet vibratory contact type which is sometimes also referred to as a current limiter and comprises an electromagnet which is here represented by the current coil 4| and a pair of vibratory switch contacts 42 and E3. The current coil 4! is a series coil which is here shown as being located in series relation in the conductor I! of the external load circuit.

The contact 42 of the vibratory contacts-of the current regulator I3 is a stationary contact. The contact 43 is a movable contact which'is carried. by an armature 44 and is urged toward a position of closed engagement with the stationary contact 42, by a tension spring 45.

The current regulator I3 also comprises a point resistor 46 which is contained in the field circuit of the generator l0 and is located in shunt relation-to the vibratory switch contacts 42 and 43 such that this resistor. willbe short-circuitedby the contacts 42 and 43 when they are in their closed position. a v

The portion of the field circuit of the generator I0 which contains the main shunt field windings 2|. and 22 has one end thereof connected with the load conductor I8 through the conductor 41 and its other end connected with the load conductor I! through the resistors 40 and 46 of the voltage and current regulators I2 and I3 and through the conductor 48. With the field circuit just described for the main shunt field windings 2| and 22, it will be observed whenever the vibratory contacts of one of the regulators l2 and I3 are open, the resistor of that regulator will be efiective as a series resistor in such field circuit and,-on the other hand, when the vibratory con tacts of either regulator are closed, the resistor of that regulator will be short-circuited out of the vfield circuit by the closed contacts.

magnet coil and the movable armature are associated. The provision of such a magnet frame in a regulator of this type is conventional in the art as is shown in prior patent 2,100,905, granted November 30, 1937, and accordingly, need not be described here in any further detail.

An important feature ofthe present invention is the provision of the auxiliary interpole field windings 25 and 25 in the generator 13 and in such circuit relation to the regulator unit H as to be controlled thereby. In the generatorregulator system of Fig. l, the auxiliary interpole windings 25 and 2B are connected with the main field circuit containing the shunt field windings 2! and 22, by means of conductors 49 and 50. The conductors 49 and 50 are connected with the main field circuit at points located on opposite sides of the resistor 40 of the voltage regulator 12 such that the energiz'ation of auxiliary interpole field windings 25 and 26 will be substantially in accordance with the voltage drop across this resistor.

Thus, when the vibratory contacts 33 and 3 E of the voltage regulator I2 are closed, the resistor 00" will be short-circuited and since the voltage drop across this resistor will then be substantially a negligible value, these auxiliary interpole field windings will be substantially deenergized. On the other hand, when the contacts 33 and 34 are open and the resistor 40 is contained in the energizing circuit for the main shunt field windings 2| and 22, there will be a substantial voltage drop across this resistor, and consequently at this time, an energizing current of a substantial value will fiow through the auxiliary interpole field windings 25 and 26.

When the speed of the generator [3 increases, the energization of the magnet coil 32 of the voltage regulator l2 Will likewise increase and the resistor 43 will then be more effective in the energizing circuit of the main shunt field wind ings 2i and 22 of the generator. At the same time, the auxiliary interpole field windings 25 and 25 will be supplied with an increased amount of excitation current as a function of the voltage across the resistor 40 of the voltage regulator.

In the generator-regulator system of Fig. l, the auxiliary interpole field windings 25 and 29 magnetically assist the main series field windings 23 and 24 of the generator 50. When the increasing speed condition of the generator causes an increased supply of excitation current to the auxiliary interpole field windings 25 and 26 through the responsive functioning of the voltage regulator l2 as just described above, the field flux produced by the auxiliary interpole windings will assist the main series field windings 23 and 2 in producing an increased flux strength in the interpole field pole members 30 and 3! of the generator. This increased flux of the interpole pole members produces the desired eliect of offsetting the increase in reactance voltage of the generator which occurs with the increase in generator speed. It will accordingly be seen from the functioning of the generator-regulator system as just described above, that the auxiliary interpole field windings, as controlled bythe voltage regulator l2, will result in the terminal voltage of the generator 10 being maintained at a desired substantially constant value throughout a Wide speed range of operation. i

It will likewise be seen that the excitation current supplied to the auxiliary interpole field windings 25 and 26 will also be controlled by the current regulator It as a function of the load current being delivered by the generator l and will limit the load current of the generator substantially to a desired maximum value. In this current control function exercised by the regulator Hi, the resistor 45 controls the excitation current being supplied to the main shunt field windings 2| and 22 and to the auxiliary interpole field windings 25 and 26 whenever this resistor is rendered effective in the field circuit by the opening of the contacts 42 and 43 of the current regulator.

The cutout device it is a conventional device which is sometimes also referred to as a reverse current relay. This cutout device comprises a pair of stationary and movable switch contacts and 52 located in the load circuit conductor l1 and a magnet having series and voltage energizing coils 53 and 54. As is understood by those skilled in this art, the cutout device It automatically connects and disconnects the genera tor It with respect to the external load and particularly with respect to the battery l9.

Fig. 3 of the drawings shows a generator-regulator system 55 which is generally similar to the system of Fig. 1, but in which the auxiliary interpole field windings and 26 are connected in the field circuit of the generator It in parallel relation to the main shunt field windings 2 l and 22 In this modified generator-regulator system 55, the auxiliary interpole field windings 25 and 26 are bucking coils, that is to say, they magnetically oppose the main series field windings 23 and 24 of the generator. In other respects the generator-regulator system 55 is substantially identical with the system of Fig. l and the same reference characters have accordingly been used to designate the other corresponding parts.

By reason of the bucking relation of the auxiliary interpole field windings 25 and 26*, relative to the main series field windings 23 and 24 and their connection in the field circuit in parallel relation to the main shunt field windings 2H and 22 it will be seen that the excitation of the auxiliary interpole field windings as controlled by the regulator unit I I will produce a condition in which the fiux of the interpole pole members and 3| of the generator will be of a substantially correct value for the minimum speed operating condition of the generator. As the speed of the generator increases, the regulator unit II will further reduce the field excitation current for the main shunt field windings Zi and 22 and for the auxiliary interpole bucking field windings 25 and 26 and a progressively stronger field fiux will accordingly be produced in the magnetic circuit of the interpole field members to offset the increase which occurs in the reactance voltage of the generator with the increase in the generator speed.

Fig. 4 of the drawings shows another modified generator-regulator system which is also similar to the generator-regulator system of Fig. 1, but in which the auxiliary interpole field windings 25 and 25 are contained in the field circuit of the generator is in a series circuit relation to the main shunt field windings 21 and 22 and in which auxiliary interpole field windings 25 and 26 are bucking coils which magnetically oppose the main series field windings 23 and 24.

Under the control of the regulator unit H, the field current being supplied to the main shunt field windings Zl and 22 and to the auxiliary interpole field windings 25 and 25*, will be reduced as the speed of the generator iii increases. An important advantage resulting from the control thus exercised on the generator I0 is that the increased flux strength of the interpole field members 30 and 3| of the generator under these conditions will provide decidedly improved commutation for the generator over a wide speed range of operation and which improved commutation condition has not been attainable heretofore.

From the foregoing detailed description and the accompanying drawings, it will now be readily understood that this invention provides an improved generator-regulator system which is especially applicable to variable speed generators such as those employed in vehicle electrical systerns and provides novel regulating means for automatically controlling the functioning of the generator and affording improved commutation therefor over a wide range of speed. Additionally, it will be seen that the present invention provides an improved generator-regulator system in which regulating means is effective on the generator through the use of auxiliary interpole field windings whose excitation is controlled by the regulating means.

Although the improved alternator-regulator system and the novel regulating means of the present invention have been illustrated and described herein to a somewhat detailed extent, it will be understood, of course, that the invention is not to be regarded as being limited correspondingly in scope but includes all changes and modifications coming within the terms of the claims hereof.

Having thus described my invention, I claim:

.1. In a generating system, a generator having load terminals and also having main and interpole field windings of which said main field windings are shunt field windings and said interpole field windings are series field windings, a voltage regulator comprising a voltage magnet coil connected across said terminals and a first pair of vibratory switch contacts responsive to the energization of said voltage magnet coil, said voltage regulator also comprising a first resistor shunting said first pair of switch contacts and adapted to be shortcircuited thereby, a current regulator comprising a series magnet coil connected in series with said terminals and a second pair of vibratory switch contacts responsive to the energization of said series magnet coil, said current regulator also comprising a second resistor shunting said second pair of vibratory contacts and adapted to be short-circuited thereby, control field windings associated with said interpole field windings, a field circuit connecting said main shunt field windings with said terminals through the switch contacts and resistors of said voltage and current regulators, and circuit means connecting said control field windings in said field circuit for energization substantially in accordance with the voltage drop across said first resistor.

2. A generating system as defined in claim 1, in which said control field windings magnetically assist said interpole field windings.

3. In a generating system; a generator having load terminals and also having main field poles carrying shunt field windings, and auxiliary field poles in interpole relation to said main field poles and carrying series field windings and control field windings; a voltage regulator comprising a voltage magnet coil connected across said terminals, and vibratory switch contacts responsive to the energization of said voltage coil; said voltage regulator also comprising a resistor shunting said switch contacts and adapted to be short-circuited thereby; a field-circuitconnecting said shunt field windings with said terminals through the switch contacts and resistor of said voltage regulator; and circuit means connecting said control field windings in said field circuit for energization substantially in accordance with the voltage drop across said resistor.

4. A generating system as defined in claim 3 in which said control field windings magnetically assist said series field windings.

References Cited in the file of this patent UNITED STATES PATENTS Number Number Number Name Date Parker Aug. 19, 1919 Turbayne Dec. 23, 1919 Haddrell Feb 5, 1929 McNeil May 23, 1933 Rady et al July 7, 1936 Leece Nov. 30, 1937 Creveling Oct. 25, 1933 Creveling Mar. 4, 1941 Webb May 3, 1949 FOREIGN PATENTS Country Date Great Britain Aug. 6, 1913 Great Britain Dec. 31, 1919 France Sept. 16, 1935 

